HP PLotter Questions

[esoteric]

Archived from groups: comp.sys.hp.hardware (More info?)

Hello all,

On the inkjet type plotters (650, 750 and newer) there is an array of
inkjets similar to inkjet printers. For the sake of this discussion I will
only deal with the monochrome print head & lets say that the array is 10
jets wide and 10 high. (I don't know the actual array size)

My question is this:

During plotting/printing do the jets in the array all fire independently of
each other, - OR - can two or more jets fire simultaneously (plot
faster) -OR - both scenarios are possible (depending on the software driving
the plot).

I understand that it may appear as though two or more jets fire at the same
time, but if all jets were monitored on an o-scope would a delay in firing
be present between jets and if so - how much of a delay?

Someone told me that it can be either way, it just depends on what software
driver is used to interface with the plotter.

Any ideas? Also is it the same across the board - HP, Calcomp, Houston
Inst. etc.?

I am actually looking for a scenario where the jets fire independently of
each other.

Thank you in advance,

Wayne C

 

[Guest]

Archived from groups: comp.sys.hp.hardware (More info?)

"Esoteric" <esotericah AT comcast DOT net> wrote in message
news:X5GdnU_RO7wtAVfd4p2dnA@comcast.com...

> On the inkjet type plotters (650, 750 and newer) there is an array of
> inkjets similar to inkjet printers. For the sake of this discussion I will
> only deal with the monochrome print head & lets say that the array is 10
> jets wide and 10 high. (I don't know the actual array size)

Logically the printhead may be an array of 600 nozzles high, one wide. It may
be laid out as two columns of 300 nozzles offset slightly.

> My question is this:
>
> During plotting/printing do the jets in the array all fire independently of
> each other, - OR - can two or more jets fire simultaneously (plot
> faster) -OR - both scenarios are possible (depending on the software driving
> the plot).

Typically the nozzles fire in groups, with the groups cycling in a fixed
manner.

> I understand that it may appear as though two or more jets fire at the same
> time, but if all jets were monitored on an o-scope would a delay in firing
> be present between jets and if so - how much of a delay?

This will depend on what is being printed and what printmodes and media are
selected and which jets you wer looking at. If you were printing a single thin
line a single nozzle would be firing at one time with a repetition rate of
perhaps 10-30Khz depending on a number of factors. You could examine a
printhead under a microscope - although the nozzles appear to be in a line
there are groups of nozzles with different offsets. Nozzles with the same
offset would print at the same time (depending on the data). The delay between
nozzles of different offsets would be on the order of several microseconds.

> Someone told me that it can be either way, it just depends on what software
> driver is used to interface with the plotter.
>
> Any ideas? Also is it the same across the board - HP, Calcomp, Houston
> Inst. etc.?

The specifics would change from manufacturer to manufacturer, as well as
differences from model to model within a manufacturer.

> I am actually looking for a scenario where the jets fire independently of
> each other.

To fire independently you would need to design a print file with "dots" at the
right places. Generally the faster printmodes will print dots on paper with a
single nozzle firing. The slower or higher quality modes may put multiple
nozzle firings on the same dot after moving the printhead.

Just curious - what do you want to do?

Regards,
Bb Headrick, not speaking for my employer HP